Electric plug-switch



`No Model.) l

A. H. PALMER. ELECTRIC PLUG- SWITCH.

10.531,424.. Patentednao. 25,1894.

UNITED STATns PATENT OFFICE.

AUGUSTUS H. PALMER, or UTICA, NEW YORK.`

LEc-rmc PLUG-SWITCH.

SPECIFICATION forminglpart of Letters Patent No. 531,424, dated December 25, 1894. Application iiled October 17. 1894. Serial No. 526,170. (No model.)

To @ZZ whom it mag/concern:

Be it known that I, AUGUSTUS H.`PALMER, of Utica, in the county ofk Oneida and State of New York, have invented certain new and usef ful Improvementsin Electric Plug-Switches;

and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in lar letters and numerals of reference refer to corresponding parts in 'the several figures, Figure 1 shows a face view of a part of the switch-board fitted with my improved plug switches. Fig. 2 shows a vertical section of the board. Fig. 3 shows in detail the switching mechanism and plug which are used in the switch, or, as it is commonly termed, jack. Fig. 4 shows the p switching mechanism or jack with the plug removed. Fig. 5 shows a plan view of the switching mechanism or jacket Referring to the reference figures and letters in a more particular description of the device, l indicates the face of the switch-board, provided, as is usual, with a shoulder-like offset 2 on which the plugs 3 rest when not in use, and beneath which are provided weigh ts 4 or equivalent mechanism for taking up slack in the connections 3 between the plugs. The switch or jack 5 is provided with a faceplate 5, preferably of circular form, and partially letinto the face of the board, as shown in Fig. 2, and secured therein by a screw 5". The face-plate is provided with a plug opening 5 and a slotted opening 5d. From the rear of the face-plateprojects a rigid arm 5e to which is secured one end of the spring 6. The free end of the spring 6 extends to a position opposite the plug opening 5 where it is provided with a shoulder 6a occupying a position, when the plug is not inserted, opposite the plug opening 5. The spring is then bent and continued through the slotted opening 5d and bent again to form the shield 6b for the opening 5d. It is then bent to form the projecting lip 6 which can be pressed downward to operate the spring.

For supporting the Vspring 6 and strengthening it so as to enable it towithstand the pressure of the plug when placed in the plughole 5 without operating the spring, I provide an L-shaped supporting varm 7 secured to the rigid projection 5 at the same point that the spring is secured. On the rear face of the face-plate 5a is also provided a stud 8 of a length. to substantially extend through the switch-board l, and on the rear end is adapted to be attached, by means. of screws and washers 89', or other suitable means, the line wire 8. Onthe rear of the switch-board 1 are provided contact conductor pieces 10. To these conductor pieces are attached the ground wires 11 passing through the annunciatorrA, and when the plug is not in position, the upper portion or arm of the spring 6 engages the piece 10 and establishes an electrical connection between line-wire 9 and the ground-wires 1l.

In describing the operation of the device, we will assume that a/telephone subscribers line-wire 9 is attached to each of the i jacks and that normally they are in the position shown in Fig. 4 and the left-hand portion of Fig. l. In the circuit with the subscriber can j also be provided tell-tales for calling the operators attention. When the subscriber calls, the operator connects the subscriber with any other subscriberv by taking one of the plugs 3 and placing the linger on the projection 6 of the jack and depressing -the same so as to free the opening 5 and allow the plug to be inserted into the position shown in the upper portion vof Fig. 2. In doing this, the connection between the spring 6 and the contact pieces 10 is broken. The-other plug 3 of the pair isv inserted in the subscriber called by depressing the spring 6 by means of the projection 6 and placing the plugin. Two subscribers are then connected. There may also be introducedin the connection 3 of each pair of plugs a tell-tale as is common, if desired. To disconnect, the operator simply withdraws the plugs 3 from the respective IOO jacks into which they have been placed,

- and when withdrawn the spring 6 moves from the position shown in Fig. 3 to that shown in Fig. 4, establishing the ground connection with each subscribers line-wire.

It may be noted that the jack cannot be operated and the plug inserted except by the operator depressing the spring by means of the projecting lip 6c of the spring, thus obviating any possibility of putting the plug in position where it would appear to be performing its oftice, when in reality it was performing no function whatever, on account of the ground not having been broken.

In the use of this device, the ground must be fully and completely broken before the plug can be inserted. When the plug is withdrawn, the device automatically closes the ground circuit, thus obviating extra work on the part of the operator in closing the ground circuit.

In practice, it is fQLlnd that operators are liable to forget to close the ground, Gill'cuit after disconnecting a subscriber; but my device automatically does this, and the subscriber is always in position to, call the oiiice.

What I claim as new, and desire to secure by Letters Patent, is

1. The plug switch or jack herein de-V scribed, having the face-plate or body with a plug opening, a spring having a shoulder closing the opening against the plug, and a and a conductor with which the spring is adapted to engage when the plug is removed, combined, substantially as set forth.

2. The combination in a plug switch or jack, of a body or face-plate having a plug opening and a line-Wire connection, a spring attached to the back of the plate and having a shoulder on its movable end closing the plug opening against the plug, and also having a projection through the face of the plate by means of which the spring may be operated, and a conductor with which the spring will engage when the plug is removed, substantially as set forth.

3. A plug switch having a body, a plug opening in the body, a spring secured to the body having a shoulder on the. free end adapted to close the plug opening against the plug, means for operating thefree end of the spring to free the plug opening, and a contact piece with which the free arm ofthe spring is adapted to engage, combined, substantially as set forth.

In witness whereof I have affixed my signature in presence of two witnesses.

AUGUSTUS II. PALMER.

Witnesses:

GEO. A. GAYMONDS, DWIGHT H. COLEGROVE. 

